July 25, 2007

In Microsoft SQL Server, a database server has logins and each database has users. Every user is associated to one login. If you detach a database from one server and move it to another (or, equivalently, backup and restore to a different machine) then your user is no longer associated to a valid login. This happens even if you have a login on the new machine with the same name as on the old machine.

Effect? No access.

It's easy to fix, though. As sa, run this stored procedure in the affected database:

July 01, 2007

This is intended as a quick update for those who follow this blog (ie: have it in their RSS reader) for their own amusement. I have just surfaced from the Great Busy Period and have started to have a bit of a life again. The past few months have been totally consumed by my Literature Review at JCU and building and launching the SonyRewards website at work.

Both are now done!

Current projects:

Setting up my new MacBook Pro - this thing is soooo cool. TextMate is an awesome editor. Recommendations for Mac software are most welcome.

Virtual Worlds for Astronomy Collaboration - experimenting with a few colleagues on using a 3D interactive environment for astronomy simulation and education. This is potentially very interesting, but it's really just in its infancy.

November 02, 2006

It was deceptively clear tonight. I say deceptively, because upon setting up my 'scope on my balcony, it quickly became apparent that the air, while clear, was very turbulent. Shake, shake, shake went the image. No imaging tonight!

The human eye is an excellent video camera, though. It knows how to take the one moment of perfect conditions and let the mind explore it for much longer than it actually lasts.

The Moon was 11.8 days old today. The crater Vieta was extremely prominent on the terminator, and seeing was occasionally good enough to see the smaller craters within it. Overall, the whole complex from Vieta to Henry was mesmerising. A decent photo of what I saw was taken by the New Millennium Observatory.

Note the new "observations" category. This is really mostly for my own reference in future years. I don't expect that too many people will be interested in reading it.

October 23, 2006

I haven't blogged for ages, so it's time for a post! I was hoping to put up more photos, but the sky has not been cooperative. I got a new camera in August (Pentax K100D - great device), and the weather has naturally conspired to give Toronto nothing but clouds since.

I attended DemoCamp10 tonight. It was the first time I've ever been to any of the BarCamp related events. It was pretty fun! They had presentations from geeks in TO doing geeky things. Whoever thought that you could have a commercial Smalltalk hosting company? Whoever thought that you could simultaneous run CRM, email, a webserver and an IRC client in emacs? Now I know.

I have been attending quite a few presentations and lectures lately. I've been a member of the RASCToronto Centre for a few years, and they put on two monthly meetings. One is a lecture by a visiting scientist (or, in one case, a science fiction author), and the other is a series of short presentations by members, much like DemoCamp. There were no meetings over the summer, so the beginning of the Fall season has really turned my interest back to discourse.

If you're not in TO, I'm sure you can find something. The U of A used to have Friday afternoon physics colloquia (with refreshments!) and the RASC has a chapter in most large- and medium-sized Canadian cities. For those on the West Coast of the US, check out the Astronomical Society of the Pacific, which is similar. No matter where you are, the Planetary Radio podcast series is decent.

June 04, 2006

Tonight was somewhat clear, so I hauled out the 'scope and set my sites on Jupiter. The clouds were annoying from time to time, but the real difficulty was turbulent air.

In any case, I'll show what I have. These images have been heavily processed and enlarged for your enjoyment. North is up, and East is right (which is backwards for a sky map).

This is Jupiter alone. I used a low frame rate (5/sec) for this image, and had only a couple of hundred frames to stack to create this. Nevertheless, I think that it turned out quite well. The dyadic wavelets work wonders on this planet! It still doesn't quite compare to being at the eyepiece, though.

This is a partial "family portrait." The moons shown are (from left to right) Europa, Io and Ganymede. Ganymede is just emerging from behind Jupiter and swinging out. The image quality is not quite as good here. I was using 30 frames/sec with the maximum shutter opening to catch the moons.

April 09, 2006

Saturn is definitely one of my favorite telescopic targets. It is a tough one to image in detail, though. It is currently 8.825 AU away (or 1.31 billion kilometers, for those who prefer metric) and that means that the planet itself (not the rings) subtends an angle of only 19 arcminutes (0.32 degrees). Even at 308X magnification (which is what my telescope (1540mm focal length) plus my Neximage webcam (5mm focal length) give, that's still an awfully small image. Also consider that 300X magnification is getting quite close to both the theoretical limits of my 127mm telescope, and to the best that can be expected from the Earth's turbulent atmosphere.

This image is the best I was able to tease out of 30 minutes of imaging. I learned a valuable lesson: a webcam's "automatic" imaging settings are very poorly suited to small, dim objects on a very black background.

You can clearly see the shadow of the rings on the planet, and the shadow of the planet on the rings. You can also pick out a hint of a cloud band in the lower hemisphere. The Encke gap between the rings is not visible. It is small enough that it exceeds the resolution of my telescope. Larger amateur instruments (twice the diameter) can resolve it.

Image taken on April 9, 2006 between 10:00pm and 10:30pm EDT. 127mm f/12.1 telescope with a 5mm focal length Neximage webcam. Processing in Registax.

It was a clear night tonight, and the Moon was well positioned for photography. Have a look at what I accomplished. Click the images to make them big.

This is Mare Crisium, which is approximately 640km on each side. Above, and to the right, is Mare Tranquilitatis, which is much larger. The Apollo 11 landing site is not visible in this image. The overexposed area is the crater Fredholm and its surroundings. This image is not oriented.

The right side of this image is not the edge of the moon, but the terminator. It separates lunar night from lunar day. The prominent crater with the central mountain is Gassendi, which is about 114 km across. Gassendi A and Gassendi B are the two craters that are immediately north of it. Mare Humorum is to the south, and Oceanus Procellarum to the north. The heavily eroded crater Letronne is also visible. The northern wall of this crater was destroyed when the lava flow that created Oceanus Procellarum overran it. This image is oriented with south to the top (a common convention, as most telescopes invert the image).

This image shows a substantial part of Mare Imbrium. The "bay" toward the bottom is Sinus Iridum, which is approximately 411 km across. The crater on its rim is Bianchini. The three prominent craters near the bay are, from top to bottom, Mairan, Sharp, and Harpalus. The two larger craters on the Mare in the upper half of the image are, from top to bottom, Diophantus and Delisle. The crater at the extreme right is Aristarchus. In between Aristarchus and Diophantus, you can see the eroded crater Prinz. It also had one wall covered with lava when this Mare formed. This image is oriented with south roughly to the top.

All identification of features was done using Virtual Moon Atlas 3.0 Expert by Legrand and Chevalley. It's a cool piece of software that's worth checking out.

All images were taken on the night of April 9, 2006 between 9:00pm and 10:00pm EDT using a Celestron Neximage webcam. Processing was done using Registax.